In this world, the bridge is an important part of roads whenever it is. In history, if there had an evaluation of transportation, the new demand for bridge load, width of span and etc come out. That will push the development of bridge project technology. Before the advent of the railway in the 1920s, the main material for bridge is stone and wood, and use the metal material is infrequent.
After the come out of the railway, the basic bridge technology for wood bridge, stone bridge can not handle the request. But at the end of 19th century, because of the spread of basic knowledge of structural mechanics, great steel production, fully-fledged pneumatic caisson technology, those things make the railroad bridge get huge development. In the 19th and 20th centuries, North America continuously set a world record in the span of railway steel bridges. Before World War 2, the span records of the highway steel bridge and the reinforced concrete bridge exceeded the railway bridge.
After World War 2, lots of bridge that was destroyed need to get restored, and need to build a lot of new bridge. But the steel that use for the bridge is short. So people use the experience of high strength material and high-efficiency technology to make several types of bridge.
- Cast-iron arch bridge
After the factory can use the coke to product big casting, the cast-iron arch bridge comes out. In 1779, the United Kingdom first built a cast iron rib arch bridge with a main span of about 30.5 meters in Colbrookdale. The bridge has been used for nearly 170 years and is now protected as a cultural relic.
From the 1920s to the end of the 19th century, in the early days of railways, railway bridges in Western Europe mainly used stone arches and cast iron rib arches. In 1849, Britain used this method to build a 6×37.8-meter double-layer (the upper layer is the railway and the lower layer is the road) cast iron arch bridge in Newcastle. The United States and Russia use wooden bridges more frequently; wooden bridges are often used for the bridges across the valley, and wooden arches and wooden truss beam bridges are used for the long-span bridges that cross the river. The appearance of wrought iron and steel has gradually changed the appearance of railway bridges. In 1845, the British J. Smith invented the steam pile driver; in 1851, the United Kingdom used a pneumatic caisson foundation (sinking depth of 18.5 meters) in the construction of a bridge in Rochester, thus ending the history of deepwater rivers unable to repair bridges.
- Cast Iron Bridge
In 1832, the United Kingdom began to build beam bridges with 1-section wrought iron in Glasgow. The span of this bridge later reached 9.6 meters. In the 1940s, the United Kingdom was going to build a large-span railway bridge that crossed the Menai Strait. The cast iron arch bridge could not meet the Navy ’s requirements for the clearance below the bridge, and the suspension bridge was not rigid enough. R. Stephenson, the person in charge of building the railway at the time, believed that: a huge box tube made of wrought iron profiles, large enough to accommodate the passing of railway trains, its rigidity can be greatly improved High; then use the stone tower to support the iron suspension cable, and use the boom to hang the box tube under the suspension cable, presumably feasible. Because he did not understand mechanical calculations at that time (C.-LM-H. Navi in France proposed the elastic beam theory in 1842, but the British engineering community did not know it), but he successfully determined the box tube beam by structural testing. The cross-sectional shape and details; at the same time, it also proves that the bridge has enough foot without suspension cable = sufficient rigidity. But the stone bridge was still built. The bridge was built between 1845-1850. Since the tests conducted during the construction of the bridge confirmed the reliability of the solid web beams, steel plate beam bridges were generally used in small-span railway bridges from the late 19th century until the steel bars were gradually reinforced until the 1950s Replaced by concrete beams.
- Steel Bridge
After 1950, the internal force analysis method of statically determinate steel truss beam is gradually mastered by the engineering community. People use more and more steel to make bridges. Bridge steel is a steel plate specially used to build railway or highway bridges. It is required to have high strength, toughness and withstand the load and impact of locomotives, and have good fatigue resistance, certain low-temperature toughness and atmospheric corrosion resistance. Steel makes the world get more possible to get better, bridge steel is just one type of steel. It also including alloy steel, high speed steel and more. And d2 steel for sale compare with 4140 steel is close, because thery are the most popular steel of alloy steels. They are good material for bridge project machines.
Technology leads the life and the world. Steel material makes the bridge get stronger and better. Not just the bridge industry, it impacts lots of industry.